1. The Field of the Invention
The present invention relates to valves, and, in particular, relates to hemostasis valves. More particularly, the invention relates to an adjustable hemostasis valve having a selecting mechanism that may maintain a valve seal in a proscribed position.
2. The Prior State of the Art
Several current surgical procedures require temporary and often repeated introduction of catheters and/or guidewires into the cardiovascular system of a patient. For example, using only a relatively small incision, a catheter can be introduced into the body of a patient and used to deliver fluid, such as medication, directly to a predetermined location within the cardiovascular system. Catheters can also be used for exploratory surgery and for removing tissue samples within a body. One increasingly common use for catheters is in the placement of small balloons that can be selectively inflated within a blood vessel. The balloons are used for opening blood vessels that have been blocked or partially blocked by plaque build-up. This opening or altering of the vein is referred to as angioplasty.
A common catheter design used in performing many of the procedures includes an elongated, flexible, cylindrical catheter body having a fluid flow passageway or a lumen extending along the interior of that catheter body. During one type of use, an end of the catheter is inserted into the body of the patient through an incision in a blood vessel in the cardiovascular system. The catheter is advanced along the internal passageway of the vessel until the end of the catheter is located at a desired predetermined location for conducting and intended activity.
A guidewire is a long, cylindrical, flexible wire that is commonly used for directing the catheter to the desired location within the body. A guidewire is typically smaller in diameter and more rigid than a catheter. It is, therefore, easier for a surgeon to first direct and advance a catheter within the cardiovascular system to the desired location within the body of the patient. The opposing end of the guidewire, positioned outside the body of the patient, is then received within the lumen of the catheter. Using the guidewire as a guide, the catheter is advanced along the length of the guidewire so as to properly position the catheter within the body of the patient. If desired, the guidewire can then be removed from within the catheter to open the lumen of the catheter. In an alternative process for inserting the catheter, the guidewire is initially received within the lumen of the catheter and the catheter and guidewire are simultaneously advanced within the cardiovascular system of the patient.
Operations using catheters can often require the insertion and removal of several different types of catheters and guidewires. One of the problems encountered with the insertion and removal of catheters and guidewires is controlling bleeding at the point where the catheters and guidewires are first introduced into the cardiovascular system.
In one approach to controlling bleeding and insuring easy insertion and removal of the catheter and/or guidewire within the cardiovascular system, one end of an introducer is first secured within a large vein of a patient. An introducer is a relatively large, hollow tube. The opposite end of the introducer is positioned outside the body of the patient and is attached to an adapter.
An adapter typically comprises a short, rigid tube having a passageway extending therethrough. Attached at one end of the adapter tube is a connector. The connector is used to connect the passageway of the adapter to the exposed end of the introducer. This enables fluids and/or medical instruments, such as catheters and guidewires, to pass between the adapter and the introducer.
Positioned at the opposite end of the adapter tube is a valve commonly referred to as a valve apparatus. The valve apparatus includes an enlarged chamber portion at the end of the adapter remote from the patient. The chamber is aligned with and is connected to the passageway extending through the adapter. Positioned within the chamber is some type of seal. During use of the adapter, the pressure of the blood causes blood from the patient to flow up through the introducer and into the passageway of the adapter tube. The seal, which either closes independently or is compressed around the catheter or guidewire, restricts blood from spilling out of the adapter through the access of the valve.
Various seal arrangements are available with different types of valve apparatus ranging from one seal to a plurality of seals. One of the main purposes of the valve arrangement is to be able to block off the passageway to stop the loss of bodily fluids from the valve apparatus. One type of seal that has been used in valve apparatus is a soft, cylindrical, compressible seal. The compressible seal has a passageway extending along the length of the seal. The seal is oriented in the chamber so that the passageway in the seal is aligned with and connected to the passage in the adapter tube.
To seal the valve apparatus that incorporates a compressible seal, a portion of the valve apparatus is advanced, typically a shaft, which in turn compresses the seal within the chamber. Compression of the seal causes the passageway in the compressible seal to constrict. If the shaft is advanced sufficiently far within the chamber, the passageway in the seal constricts so as to form a seal around the exterior surface of the catheter or guidewire positioned in the passageway. Alternatively, if the catheter or guidewire is removed from within the seal, the passageway in the seal can constrict in response to compression force so that the seal completely closes off the access through the valve.
Current designs that utilize compressible seals require the compressive force to be removed from the compressive seal in order to remove the catheter or guidewire from the valve apparatus. Removing the compression force often required rotating the end portion of the valve apparatus or some other way of incrementally removing the force. The present methods of removing the force take some amount of time that results in a needless loss of blood and increases the risk of contamination of the blood of the patient. It is important to be able to quickly make adjustments or insert/remove the guidewire or catheter without unnecessary time passing. Furthermore, leaking bodily fluids, including blood, may produce both a messy and slippery work environment for the surgeons. With the increasing number of blood disorders such as AIDS, blood leakage from the adapter increases the risk to the surgeon and other medical personnel.
Attempts have been made to solve the leakage problem by making valve apparatus that utilize two or more seals. Typical seals include duck-bill valves and slit valves. While multiple seals in the valve apparatus are useful in helping to reduce the loss of body fluids, including blood, several problems still exist. Current valve apparatus, regardless of whether the valve has one or two seals, generally have an open position and a closed or sealed position. Once the valve apparatus is closed, the surgeon is not able to move or reposition the catheter or guidewire without putting the valve apparatus into the open position where body fluids can flow out the valve. For example, if the valve utilizes a compressible seal, the catheter or guidewire cannot be repositioned or removed unless substantially all of the compressive force is removed from the compressible seal. Once the compression force is removed, the valve apparatus is no longer sealed. The available valve apparatus are not configured to provide a seal against a loss of bodily fluids while still allowing the catheter or guidewire within the valve to be repositioned.
An additional problem with existing valve apparatus is that the seals, and in particular those seals that are compressed to form a seal, tend to exert a force upon the catheter or guidewire. The forces, including the frictional forces acting on the instrument, are commonly referred to as xe2x80x9cdrag.xe2x80x9d The drag acting on the catheter or guidewire disposed in a seal makes it difficult for the surgeon to be able to adjust the catheter or guidewire. In particular, it is very difficult to be able to adjust the catheter or guidewire by the xe2x80x9cfeelxe2x80x9d of the movement. Currently, the valve apparatus must be adjusted to remove the compression forces acting on the seal. Removing the compression forces acting on the seal results in fluid leakage.
Some other valve apparatuses utilize a mechanism that allows the user to manually control the sealing forces applied to a compressive seal during insertion, removal, or readjustment of a catheter or guidewire. The valve apparatuses require the compressive force to be removed from the compressive seal in order to remove the catheter or guidewire from the valve. Unfortunately, even modem valve apparatuses are cumbersome to seal and unseal and maintain in a sealed or an adjusted position during a particular procedure. Finally, having to remove the compression force, reposition or remove the catheter or guidewire, and then readjust the valve apparatus to compress the seal so as to form a seal is time consuming and in turn unnecessarily lengthens the procedure.
It will be desirable to have a valve apparatus that may be quickly sealed and adjusted to reposition or remove a catheter or guidewire without having to remove the compression forces and is able to minimize blood leakage from the valve apparatus, or reset the desired amount of drag acting upon the guidewire or catheter. It would also be advantageous to have a valve apparatus in which the seal will remain sealed but will allow an instrument such as a catheter or guidewire to be longitudinally repositioned without exerting so much drag on the catheter or the guidewire that the surgeon is unable to have a feel for the movement of the guidewire or catheter.
It is therefore an object of the present invention to provide a valve apparatus that can be quickly unsealed and resealed to minimize the loss of body fluids without the need to continually use one or more hands of the user while the compressive force is released.
Another object of the present invention is to provide a valve apparatus that substantially eliminates the need to re-adjust the compressive forces applied to the seal upon resealing the seal when insertion, removal, and repositioning of a catheter or guidewire is completed.
Still another object of the present invention is to provide a valve apparatus that may maintain a seal in either a sealed or selectively adjusted position without the need for the user, such as a physician or nurse to manually maintain the seal in one of those positions.
Yet another object of the present invention is to provide a valve apparatus that allows a practitioner to quickly unseal the valve apparatus with a simple motion to allow the practitioner to remove a catheter or guidewire, while automatically completely sealing the valve apparatus upon discontinuing the simple motion.
It is another object of the present invention to provide a valve apparatus that can be quickly unsealed and resealed to minimize the loss of body fluids while repositioning or removing medical instruments from the valve apparatus.
It is another object of the present invention to provide a valve apparatus that can be unsealed and resealed in a simple motion.
It is another object of the present invention to provide a valve apparatus that can be adjusted to have a desired seal, then quickly unsealed and resealed such that upon being resealed the valve apparatus will return to have substantially the same seal as before the valve apparatus was unsealed.
It is another object of the present invention to provide a valve apparatus that is capable of being sealed to prevent the loss of body fluids while still allowing longitudinal movement of the catheter or guidewire disposed in the valve apparatus.
It is still yet another object of the present invention to provide a valve apparatus that includes a compressible seal which allows the valve apparatus to be sealed while still allowing the catheter or guidewire to be longitudinally repositioned without having to completely remove the compressive forces acting on the seal.
It is yet another object of the present invention to provide a valve apparatus in which the mechanical forces acting on the catheter or guidewire while the catheter or guidewire is being repositioned can be selectively reduced or increased while a seal is maintained within a sealing window.
Still another object of the present invention is to provide a valve apparatus that allows the repositioning or removal of the catheter or guidewire with increased speed and substantially without the loss of body fluids.
Yet another object is to provide a valve apparatus that incorporates a compressible seal but enables a surgeon to move or reposition a catheter or seal by xe2x80x9cfeelxe2x80x9d while still maintaining a sealed configuration in the valve.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims.
To achieve the foregoing objects, and in accordance with the invention as embodied and broadly described herein, a hemostasis valve is provided that has a quick-release and/or selecting mechanism and an improved valve assembly that minimizes the loss of body fluids during repositioning or removing of medical instruments, such as catheters and guidewires, from the valve apparatus. The valve assembly includes a compressible seal that responds to compressive forces exerted thereon to seal the hemostasis valve. When compressive forces are progressively exerted on the compressible seal, a portion of the seal moves radially inward to form a progressively tighter seal around a catheter or guidewire that is disposed within the compressive seal. The amount of compressive force exerted on the compressible seal can be incrementally adjusted so that a seal is formed or maintained around the catheter or guidewire while still allowing the catheter or guidewire to be longitudinally repositioned or removed without having to remove substantially all of the compressive forces acting on the compressible seal.
In addition, in one embodiment, the quick-release mechanism enables the valve apparatus to be completely opened and closed in a single, or relatively simple, movement for even quicker adjustments of the catheter or guidewire disposed therein. The quick-release mechanism can be selectively moved between an activated position and an inactivated position. When the quick-release mechanism is in the inactivated position, the valve assembly can be incrementally opened or closed depending on the amount of force acting on the compressible seal. When the quick-release mechanism is moved to the activated position, however, some or all of the compressive force is removed from the compressible seal, depending on the embodiment. Upon returning the quick-release mechanism back to the inactivated position, the compressible seal will return to substantially the same position with substantially the same amount or tightness of seal as before the quick-release mechanism was activated. The compressive forces acting on the compressible seal do not have to be removed or even adjusted prior to or after using the quick-release mechanism, since the original adjustment will be restored upon deactivating the quick-release mechanism.
In particular, in one embodiment, the valve apparatus comprises a tubular body, a compressible seal, and a quick-release mechanism. The tubular body is generally elongated and has a lumen formed therethrough that is adapted for accessing the cardiovascular or other intravenous system of a patient. The tubular body has a distal end, a proximal end, and a compression chamber located at the proximal end thereof that is in communication with the lumen. The resilient compressible seal comprises sealing means and is disposed within the compression chamber and has a longitudinal passageway formed therethrough that is aligned with the lumen in the tubular body. The passageway in the compressible seal has a raised annular portion projecting into the passageway configured to selectively provide an opening to the lumen in the tubular body. The compressible seal is configured to selectively seal and unseal the lumen in response to a compressive force exerted on said compressible seal by selectively and progressively reducing the size of the opening provided by the raised annular portion in the passageway.
The valve apparatus, in one embodiment, also includes a quick-release mechanism and a biasing means. The quick-release mechanism comprises a lever hingedly attached to the tubular body and a quick-release assembly movably attached to the tubular body. The quick-release mechanism is selectively movable between an inactivated position in which the compressible seal is in a compressible position and an activated position in which the compressible seal is in a released position. In other words, xe2x80x9cactivatingxe2x80x9d the quick-release mechanism causes the valve to be in a released and substantially noncompressible state. The lever is selectively moved between an extended position in which the quick-release mechanism is in the inactivated position and an unextended position in which the quick-release mechanism is in the activated position. The quick-release mechanism is operably connected to the lever and is configured to move the compressible seal between the compressible position and the released position in response to the lever being selectively moved in a hinged movement toward or away from the tubular body.
The biasing means is mounted on said tubular body for urging the compressible seal into the compressible position in the compression chamber, and generally includes a spring communicating with a plunger that, in turn, can be adjusted to apply a desired amount of compressive force onto the compressible seal.
The valve apparatus also includes a rotatable end cap operably interconnected between the quick-release mechanism and the plunger for selectively adjusting and fine tuning the amount of compressive force applied to the compressible seal by the plunger. The end cap includes a shaft that is integrally formed therewith and which projects from the end cap. The shaft includes threads that engage corresponding threads within the plunger for threadably engaging the end cap and plunger such that the shaft is advanced or withdrawn within the compression chamber by rotation of the end cap. The rotatable end cap and plunger comprise a compressing mechanism that provides means for applying a desired compressive force onto the compressible seal. The biasing means may be considered to form part of the compressing means in some circumstances.
The quick-release mechanism is configured to overcome the opposing force of the biasing means in order to at least partially release the compressive force applied by the compressing means onto the sealing means. Thus, once the end cap has been rotated to a desired position to apply a desired compressive force and thereby form a desired seal, the quick-release mechanism allows the user to release the seal and then restore the desired seal in a simple motion. This allows the user to release and then restore the desired seal without having to readjust the end cap once the end cap has been rotated to a desired position in order to form a desired seal.
It would also be within the scope of the present invention to provide compressing means that applied a pre-set or predetermined level of compressive force to the sealing means such that the seal was preadjusted to a predetermined hole size and/or tightness such that the compressing means would not be adjustable. That way, the quick-release means would be used to open and then close, or unseal and then seal, the valve apparatus when desired to insert or adjust a catheter, guidewire, or other elongate device disposed within the valve apparatus.
According to another aspect of the present invention, a practitioner is able to conveniently toggle between a sealed position and a selectively adjusted position that has been set by a practitioner. This toggling capability is accomplished through the use of a lever similar to a lever of the quick-release mechanism and an internal cooperating mechanism that moves the seal between the selectively adjusted position and a sealed position. The lever and internal cooperating mechanism are components of a selecting mechanism that conveniently provides this toggling capability. In light of the selecting mechanism, it is possible for a practitioner to depress and release the lever a first time to achieve the sealed position then depress and release the lever a second time to achieve the selectively adjusted position that has been selected by the practitioner.
This convenient toggling capability enables a practitioner to move the seal at any time during a procedure to a sealed position merely by depressing and releasing the lever. By depressing the lever, as discussed with regard to the quick release mechanism, the seal is completely unsealed allowing convenient movement of a catheter through the seal during removal or insertion of the catheter. Upon releasing the lever the valve is sealed thereby preventing any loss of blood. The toggling capability thus provides the convenience of the quick-release mechanism that allows movement of a catheter through the seal and the ability to quickly seal the valve following insertion or removal of the catheter without significant loss of blood.
As mentioned, the selecting mechanism comprises a lever and an internal cooperating mechanism. By initially depressing and releasing the lever the selecting mechanism achieves an activated position in which the seal is sealed. By then depressing and releasing the lever a second time the selecting mechanism achieves an inactivated position where the seal returns to a selectively adjusted position selected by the practitioner. For example, practitioner may initially select a desired adjusted position by rotating an end cap to compress the seal a desired amount. This is a xe2x80x9cselectively adjusted position.xe2x80x9d Optionally, selectively adjusted position of the seal is unsealed, i.e., the practitioner has not rotated the end cap. In other words, the selectively adjusted position may be a completely unsealed position or a partially or even completely sealed position that has been selected through rotating the end cap. Thus, the xe2x80x9cselectively adjusted positionxe2x80x9d can be any position that is achieved through rotation or non-rotation of the end cap. The selecting mechanism is in an xe2x80x9cinactivated positionxe2x80x9d when the seal is in any of these xe2x80x9cselectively adjusted positions.xe2x80x9d
In the activated position, the internal cooperating mechanism of the selecting mechanism exerts it greatest possible force on the seal. In the inactivated position these components of the internal cooperating mechanism may exert a lesser force on the seal. The internal cooperating mechanism, in one embodiment, comprises an engagement member and a rotating member. The engagement member has alternating long and short elongate teeth that cooperate with the rotating member. When the long elongate teeth engage the rotating member the internal cooperating mechanism has a greater length. Consequently, the internal cooperating mechanism exerts its greatest force on the seal. When the short elongate teeth engage the rotating member the internal cooperating mechanism has its shortest length. When the long elongate teeth engage the rotating member the internal cooperating mechanism is in the activated position. Alternatively, when the short elongate teeth engage the rotating member the internal cooperating mechanism is in the inactivated position. As a result, the selecting mechanism automatically moves the seal back and forth between a sealed position (selecting mechanism is activated) and any partially sealed, completely sealed, or completely unsealed position that has been selectively adjusted by the practitioner (selecting mechanism is inactivated).
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.